Fuel tank liner?

Reply Subscribe

Thread Tools

Search this Thread

Feb 12, 2006 | 01:21 PM

VETTEVIC

Thread Starter

Pro

Joined: Aug 2005

Posts: 613

Likes: 2

From: West Central Florida

Fuel tank liner?

What would be the purpose of removing the fuel tank liner? Mine has a small tear on the gasket area under the sender which I am "rebuilding". It's a 76 so the tank and sender are very expensive. Also there appears to be a ring in the top of the tank which holds the closed "nuts" to bolt the sender to and the liner (bladder) seems to be between the two. Anyone removed or replaced the bladder on one of these and could give some pointers?
thanks
vic

Feb 12, 2006 | 01:39 PM

Paul Borowski

Team Owner

Joined: Aug 2000

Posts: 21,457

Likes: 463

From: Massillon,Ohio USA

2020 C3 of the Year Finalist - Unmodified

Cruise-In VI Veteran

St. Jude Donor '08-'09-'10-'11-'12

...I took my bladder out of my '75 back in '94. Due to the age of the rubber used in these "bladders", chemical additives in gasoline, etc., they seem to be "collapsing" away from the walls of the fuel tank. I bought my '75 in 1991 and it took only 12 gals of gas then. It slowly got progressively worse til it was down to about 6 gals. I know of several other '75-'77 owners where their cars also ONLY take 12-14gals to fill them up. I simply removed the top access panel that houses the fuel sending unit/pick-up tube and pulled the bladder out of the tank. I then neatly cut the top of the bladder(the part of the bladder that forms the gasket for the access panel)off and re-used this part. Re-assembled the tank this way and in less than three hours I was back on the road, this time my '75 NOW taking 18.5+ gals of fuel to fill it up.

Been this way since '94 and have put 40,000mi on it since without a hitch. Quanta now reproduces the '75-'77 gas tank(without bladder)for $149 in case your metal tank is rusty. Mine was near perfect with little surface rust and I was able to re-use it.

Feb 12, 2006 | 01:58 PM

turtlevette

Melting Slicks

Joined: Feb 2003

Posts: 3,053

Likes: 4

St. Jude Donor '03,'11

Quote:

Originally Posted by Paul Borowski

I know of several other '75-'77 owners where their cars also ONLY take 12-14gals to fill them up. .........my '75 NOW taking 18.5+ gals of fuel to fill it up. :

mine has always never taken more than 14.5 gallons since i bought it in 80. I think i'll live with the 4 gallon difference rather than burn to death when some idiot rearends me.

I get greif for some of the mods i make, but removing the tank liner is probably the single most dangerous thing you can do on these cars.

Feb 12, 2006 | 02:47 PM

VETTEVIC

Thread Starter

Pro

Joined: Aug 2005

Posts: 613

Likes: 2

From: West Central Florida

Mine is still firmly in place on the sides top and bottom of the tank. It seems that the vapor canister also vents to the space between the liner and the tank keeping the bladder from collapsing into the tank by allowing it to equalize the pressure between them. If you are losing volume though I can see the bladder being removed. Did you have to cut the bladder inside the top around the opening where the bolts go in as well as the seal on the outside?

Feb 12, 2006 | 07:29 PM

jdmick

Safety Car

Joined: Oct 2004

Posts: 3,725

Likes: 5

From: Minnesota

Dangerous as it may be, I just cut out the bladder in my 75. All you need to do is take out the dozen bolts that hold the guage/fill assembly on top of the tank. The top seal and bladder are all one unit. I removed everything and only cut the bladder away from the seal assembly. For sure the toughest part was getting the tank back up into place and getting the bottom brace back on. As far as safety goes there is a pretty stout crossmember directly behind the tank. None of the earlier cars had a bladder and none of the aftermarket tanks I know of have one either. I also haven't seen a vendor for replacement bladders. I guess I'll take my flaming Pinto chances for now.

Feb 13, 2006 | 08:12 AM

Ganey

Race Director

Joined: Apr 1999

Posts: 11,520

Likes: 13

From: CORVETTE 77 385 C.I. TEXAS

Guys esp. those who drive hard & fast

should not remove it if there is no problem. Remember race cars have safety equip.

Feb 13, 2006 | 02:34 PM

I'm Batman

Team Owner

Joined: Oct 2004

Posts: 23,831

Likes: 10

From: Springfield MO

St. Jude Donor '07

I think that if you get to the point of having an exploding gas tank, you probably have bigger issues - like the back of the frame becoming part of your head...

Feb 13, 2006 | 06:11 PM

norvalwilhelm

Race Director

Joined: Nov 2000

Posts: 11,872

Likes: 12

From: Waterloo ontario Canada

I had to remove mine from a 75 because I was putting dual fuel outlets in the bottom of the tank. I just opened up the top and pulled it out. The tank was perfect inside and I just reinstalled it after doing the dual outlets and never had a problem.